How to be polite in English

Have you ever been in the situation where you had to speak in English, but did not know what to say?
Below are some of the most common responses you can use in English when you have to be polite.

Asking for permission
Do you mind if…..
Would it be a problem if…..
I was wondering if I could…..

Not understanding
Sorry
Pardon (me)?
Excuse me?

Disagreeing
I see what you’re saying, but I think…..
You could be right, but don’t forget that…..
Yes that’s true, but I’m not sure…..

Turning down an invitation
I’m afraid I can’t…..
I’d love to but…..
That sounds great but…..

Making requests/ Asking for something
Can I/ Could I…..
May I…..